<HTML><HEAD><TITLE>det_update(+Map0, ++Key, ?Value, -Map)</TITLE>
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<H1>det_update(+Map0, ++Key, ?Value, -Map)</H1>
Update the value corresponding to a key in a map, aborting if it doesn't exist.
<DL>
<DT><EM>Map0</EM></DT>
<DD>A map
</DD>
<DT><EM>Key</EM></DT>
<DD>A key to update
</DD>
<DT><EM>Value</EM></DT>
<DD>The value corresponding to Key
</DD>
<DT><EM>Map</EM></DT>
<DD>The map after updating
</DD>
</DL>
<H2>Description</H2>
	<P>
	If the key Key already exists in the map Map0, then this
	predicate updates the corresponding value to be Value, resulting
	in the map Map.  If the key Key is not already in the map,
	then the predicate aborts with a runtime error.
	</P>
	<P>
	This predicate should only be called with maps created by other
	predicates from the map module.
	</P>
	
<H3>Fail Conditions</H3>
Never fails.
<H3>Resatisfiable</H3>
no
<H2>See Also</H2>
<A HREF="../../lib_public/m_map/update-4.html">update / 4</A>, <A HREF="../../lib_public/m_map/insert-4.html">insert / 4</A>, <A HREF="../../lib_public/m_map/det_insert-4.html">det_insert / 4</A>, <A HREF="../../lib_public/m_map/set-4.html">set / 4</A>
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